Document: KAT-3-40-3

Vegetation response to large scale disturbance in a southern Appalachian forest: Hurricane Opal and salvage logging.

ELLIOTT, K.J.* ¹, S.L.HITCHCOCK ² and L.M.KRUEGER ²

US Forest Service, Otto, NC 28763 USA ¹
Furman University, Greenville, SC 29301 USA ²

Abstract:
Disturbance such as catastrophic windthrow can play a major role in the structure and composition of southern Appalachian forests. Oct 5, 1995, the center of Hurricane Opal passed over southeastern Tennessee causing high winds and heavy rainfall in much of the southern Appalachians including the Coweeta Basin, southwestern North Carolina. The unusual size and strength of Opal, had a considerable affect on inland forest communities resulting in large-scale tree damage and subsequent salvage logging operations. Little is known about how southern Appalachian forests will respond to this type of catastrophic windthrow followed by salvage logging. In addition, information on herb responses to gaps is scarce relative to that for trees. The objective of this study was to compare herbaceous layer and tree species richness, diversity (H'; Shannon index), evenness (J'), and composition in a hurricane + salvage logged (H+S) area to an adjacent undisturbed forest. While other studies in the Coweeta Basin have documented regeneration following disturbance, this is the first study examining the effects of catastrophic windthrow on regeneration and vegetation dynamics. Abundance of herbaceous layer species was much higher in the H+S area than in the undisturbed forest and abundance increased over time. Percent cover, density and species richness were significantly higher in the H+S area than in the undisturbed forest. In addition, percent cover increased by approximately 85% between 1997 and 1999 in the H+S plots. H' based on percent cover was significantly higher in the H+S area than the undisturbed forest by the third year after disturbance. However, there was no significant difference in H' based on density between H+S area and the undisturbed forest in either year. In the undisturbed forest, 55 species and 50 genera represented 30 families. By 1999 (the third year after disturbance), the H+S area retained 83 species, 72 genera and 42 families. The Asteraceae and Liliaceae had the highest number of species in both sampled areas, with more species of Liliaceae in the H+S plots.

Keywords: hurricane, treefall, windthrow, diversity, regeneration, herbs

This abstract is being presented at: 10:30 AM in session:
Poster Session #12: Disturbance Ecology.